Electrochemical properties of carbide-derived carbon electrodes in non-aqueous electrolytes based on different Li-salts

Electrochemical characteristics of carbide-derived micro/mesoporous carbon material C(TiC) (prepared from TiC) have been studied in 1 M LiClO4, 0.5 M LiClO4 + 0.5 M LiPF6, and 1 M LiPF6 electrolyte solutions in ethylene carbonate–dimethyl carbonate solvent mixture (1:1 by volume), by using cyclic voltammetry (CV), constant current charge/discharge and electrochemical impedance spectroscopy (EIS). Region of ideal polarizability, values of series capacitance and resistance, charge transfer resistance and capacitance, and other characteristics dependent on the electrolyte anion chemical composition have been established. The dependence of Li+ ion intercalation characteristics and solid electrolyte interface (SEI) formation on the salt anion composition have been established and discussed. It was found that the three electrolytes studied are comparatively weak candidates for long-lasting high energy and power density supercapacitors.

► Supercapacitors based on mixed carbonate solvents (EC + DMC). ► TiC derived micro/mesoporous carbon as an electrode material. ► LiClO4, LiPF6 and LiClO4 + LiPF6 as electrolytes for supercapacitors. ► Nearly ideal capacitive behavior at moderate cell voltages. ► Kinetics of SEI formation slow and dependent on salt anion chemical composition.